Modular elbow

Abstract

A modular elbow prothesis includes a humeral component, an ulnar component and three bearing components. The ulnar component includes a stem for implantation in the intramedullary canal of an ulna and a body including a slot. Two of the three bearing components include flanges that mate with the slot of the ulnar component. The humeral component includes a stem for implantation in the intramedullary canal of the humerus and two arms extending from one end of the stem. An opening is formed in each arm and in two of the three bearing components. The modular elbow may be used in an unconstrained mode by attaching one bearing component to the ulnar component and the other to the humeral component by inserting a pin through the openings in the arms and the bearing component. The two bearing components are then placed adjacent each other such that they articulate about their bearing surfaces. Alternatively, the prosthesis can be utilized in a constrained mode by positioning the flange of the third bearing component in the slot on the ulnar component and positioning the third bearing component between the arms of the humeral component and inserting a pin through the openings in the arms of the third component.

What is claimed is: 
     
       1. A prosthetic joint kit, comprising: a first stem having a first end and a second end;   a body connected to the first stem;   a slot formed in the body;   a first bearing component having a bearing surface;   a flange connected to the first bearing component and configured to mate with the slot;   a second stem having a first end and a second end; a pair of arms extending from one end of the second stem;   a second bearing component adapted to fit between the arms of the second stem and configured to mate with the bearing surface of the first bearing component;   a third bearing component interchangeable with the first and second bearing components, the third bearing component being adapted to fit between the arms of the second stem; and   a flange connected to the third bearing component and configured to mate with the slot.   
     
     
       2. A prosthetic joint kit according to claim 1, fuirther comprising an opening in each of the arms, an opening in the second bearing component and a pin adapted to extend through the openings in the arms and second bearing component. 
     
     
       3. A prosthetic joint kit according to claim 1, further comprising an opening in each of the arms, an opening in the third bearing component and a pin adapted to extend through the openings in the arms and the third bearing component. 
     
     
       4. A prosthetic joint kit according to claim 1, wherein the bearing surface of the first bearing component is concave and the second bearing component includes a convex surface. 
     
     
       5. A prosthetic joint kit according to claim 1, wherein the second end of the first stem is wider than the first end of the first stem. 
     
     
       6. A prosthetic joint kit according to claim 1, wherein the second end of the second stem is wider than the first end of the second stem. 
     
     
       7. A prosthetic joint kit according to claim 2, wherein the pin includes a head having a larger diameter than the diameter of the opening in one of the arms. 
     
     
       8. A prosthetic joint kit according to claim 3, wherein the pin includes a head having a larger diameter than the diameter of the opening in one of the arms. 
     
     
       9. A prosthetic elbow kit, comprising: an ulnar component having a stem with a first end adapted to fit within the medullary canal of a ulna and a second end;   a first bearing component adapted to engage the ulnar component;   a humeral component having a stem with a first end adapted to fit within the medullary canal of a humerus;   a second bearing component adapted to engage the humeral component and mate with the first bearing component so as to be held in place by the soft tissues of the elbow; and   a third bearing component interchangeable with the first and second bearing components, the third bearing component adapted to engage the ulnar component and be held in place by the humeral component.   
     
     
       10. A prosthetic elbow kit according to claim 9, wherein the ulnar component includes a slot and the first bearing component includes a flange configured to mate with the slot. 
     
     
       11. A prosthetic elbow kit according to claim 9, wherein the humeral component includes a pair of arms and the second bearing component is adapted to fit between the arms. 
     
     
       12. A prosthetic elbow kit according to claim 11, further comprising an opening formed in each of the arms, an opening formed in the second bearing component and a pin adapted to extend through the openings in the arms and the second bearing component. 
     
     
       13. A prosthetic elbow kit according to claim 9, wherein the humeral component includes a pair of arms and the third bearing component is adapted to fit between the arms. 
     
     
       14. A prosthetic elbow kit according to claim 13, further comprising an opening formed in each of the arms, an opening formed in the third bearing component and a pin adapted to extend through the openings in the arms and the third bearing component. 
     
     
       15. A prosthetic elbow kit according to claim 9, further comprising a slot formed in the ulnar component and a flange connected to the third bearing component and configured to engage the slot. 
     
     
       16. A prosthetic elbow kit according to claim 9, further comprising a slot formed in the ulnar component, a flange connected to the first bearing component and configured to engage the slot, and a flange formed on the third bearing component and configured to engage the slot. 
     
     
       17. A prosthetic elbow kit, comprising: a plurality of bearing components, at least one of which is configured for allowing unconstrained prosthetic elbow movement and at least one of which is configured for allowing only constrained prosthetic elbow movement;   an ulnar component for attachment to a human ulna, the ulnar component having a proximal end and a distal end;   a humeral component for attachment to a human humerus, the humeral component having a proximal end and a distal end;   a first bearing mount on the humeral component for engagement with at least two of the plurality of bearing components; and   a second bearing mount on the ulnar component for engagement with at least two of the plurality of bearing components.   
     
     
       18. The prosthetic elbow kit according to claim 17, wherein the first bearing mount includes a pair of spaced apart arms extending from the humeral component. 
     
     
       19. The prosthetic elbow kit according to claim 17, wherein the first bearing mount is located at the distal end of the humeral component. 
     
     
       20. The prosthetic elbow kit according to claim 17, wherein the second bearing mount is located at the proximal end of the ulnar component. 
     
     
       21. The prosthetic elbow kit according to claim 17, wherein the second bearing mount includes a slot formed in a portion of the ulnar component. 
     
     
       22. The prosthetic elbow kit according to claim 17, wherein the first and second bearing mounts are configured to simultaneously engage one of a plurality of bearing components. 
     
     
       23. A prosthetic elbow kit, comprising: a humeral component having a bearing mount;   an ulnar component having a bearing mount;   first and second bearing components, the first bearing component configured to engage the ulnar bearing mount and the second bearing component configured to engage the humeral bearing mount and the first bearing component so as to form an unconstrained prosthetic elbow; and   a third bearing component interchangeable with the first and second bearing components and configured to engage the humeral and ulnar components so as to form a constrained prosthetic elbow.   
     
     
       24. The prosthetic elbow kit according to claim 23, wherein the humeral bearing mount includes a pair of spaced-apart arms. 
     
     
       25. The prosthetic elbow kit according to claim 23, wherein the ulnar bearing mount includes a slot. 
     
     
       26. The prosthetic elbow kit according to claim 23, wherein the third bearing component includes a cylindrical body. 
     
     
       27. The prosthetic elbow kit according to claim 26, wherein the third bearing component further includes an opening. 
     
     
       28. The prosthetic elbow kit according to claim 26, wherein the third bearing component further includes a flange. 
     
     
       29. The prosthetic elbow kit according to claim 28, wherein the flange is configured to mate with the ulnar bearing mount. 
     
     
       30. The prosthetic elbow kit according to claim 23, wherein the first bearing component includes a flange. 
     
     
       31. The prosthetic elbow kit according to claim 30, wherein the flange is configured to mate with the ulnar bearing mount. 
     
     
       32. The prosthetic elbow kit according to claim 23, wherein the humeral bearing mount includes an opening. 
     
     
       33. A prosthetic elbow kit, comprising: a humeral component;   an ulnar component;   a plurality of bearings for providing pivotal movement of the ulnar component relative to the humeral component in an unconstrained manner, at least one of the bearings being configured to attach to the humeral component and at least one being configured to attach to the ulnar component; and   a first bearing, interchangeable with the plurality of bearings, for joining the humeral and ulnar components to form a constrained prosthetic elbow.